@dcazman yes, fontsize is a brain twister
many of the html elements do not inherit settings from things above them
imagine if fontsize 50 worked on the top level of a printed page, suddenly everything would be 50…, even when you meant on this paragraph
and some other paragraph already said 20, oops…
SO, you need to find the element in the dev window elements tab and see where it got its size from (right column after you select that html element) and fix that…